Conventionally, glass plates are utilized in various fields. Glass plates (hereinafter, referred to as glass substrates) which are employed for liquid crystal displays, plasma displays, and the like, are particularly thin. A great number of glass plates are being produced, with thicknesses of approximately 0.7 mm and sizes of 550 mm×650 mm. In conventional facilities, conveyance, trimming, and cutting of these glass plates are performed with the glass plates in a horizontal state (laid down).
When processing glass plates in the horizontal state in conventional facilities, there is a possibility that the glass plates will break due to their own weight, or by forces applied thereto by structural members that support and convey the glass plates, as the glass plates become larger and thinner. In addition, processing apparatuses will become larger, the installation areas thereof increase, and costs increase if the large glass plates are processed in the horizontal state. Further, maintenance will become difficult with the increase in the size of the apparatuses.
For these reasons, the present applicant has proposed a plate material cutting system equipped with: a fluid guide, for supporting plate materials, which are processing targets, in a non-contact manner; a scribe forming device, for forming scribes for cutting (also called scribes) onto the plate materials in this state; and a cutting device, for cutting the plate materials at the scribes (refer to Japanese Unexamined Patent Publication No. 2004-167833, for example). By using this system, scribing onto plate materials can be performed without the plate materials being influenced by their own weight or supporting forces applied by structural members, then the plate materials can be cut.
However, in this system, the plate materials are conveyed in an upright state, the scribing device scribes the plate materials in the vertical direction, a rotating device rotates the plate materials 90°, the scribing device scribes the plate materials in the vertical direction (the horizontal direction prior to rotation) again, then the plate materials are conveyed to the cutting device, to perform cutting at the scribes (including trimming of the peripheral edges of the plate materials).
In this manner, it is necessary to convey the plate materials to the cutting device after they are scribed by the scribing device. In addition, the scribing device and the cutting device have dimensions in their conveyance directions, which are much longer than the widths of the plate materials, and it is necessary to install both the scribing device and the cutting device, in order to cut the plate materials. Accordingly, the system as a whole becomes greatly elongated. In addition, conventional rotating devices rotate plate materials with the lower corners thereof as the center of rotation, and therefore, it is necessary for the width of the rotating device to be twice that of the plate material or greater.
Recently, glass plates for liquid crystal panels are becoming larger. Therefore, the length and size of the system need to be made even larger. There is a problem that such a large system cannot be installed in existing facilities.
The present invention has been developed to solve the aforementioned problem. It is an object of the present invention to provide a compact plate material cutting unit capable of scribing and cutting plate materials, such as large thin glass plates, without reducing the quality of the cut plate materials. It is another object of the present invention to provide a cutting apparatus equipped with the plate material cutting unit. It is still another object of the present invention to provide a system equipped with the cutting apparatus.